This invention relates to a corner region between the lateral and rear roof frame of a motor vehicle having a rear door, and to a method for producing it.
In conventional motor vehicles having a rear door, a large number of plates are used in the body shell in order to confer the required stiffness and strength of the corner region between the lateral and the rear roof frame, since the corner region, which comprises sheet-metal shells of the lateral roof frame, is open toward the rear of the vehicle in order to hold a hinge for the rear door and is therefore weakened. In this case, work has to be carried out in a very complex manner with seam-sealing material in order to prevent water which penetrates into the hinge opening from being able to pass into the interior of the vehicle and the rest of the body shell.
The invention is based on the object of developing a corner region between the lateral and rear roof frame of a motor vehicle having a rear door and a method for producing it to the effect that the absorption of mechanical forces acting on the body shell in the roof region is improved in a simple manner.
This object is achieved according to the invention by the features of claim 1 in respect of the corner region and by the features of claim 10 in respect of the production method.
Owing to the fact that a junction component consisting of a hollow profile is used for the corner region, high stiffness and strength is provided for this region. This is all the more so if the hollow profile is a single-piece component which is formed from a tubular blank. Single-piece formation means that the body shell is very greatly simplified structurally and in terms of manufacturing at this point and the multiplicity of parts is drastically reduced, and at the same time forces which act from the outside, in particular in a crash, can be considerably better absorbed by the lateral and rear roof frame and the D-pillar and can be transferred without stress concentrations. It is true that because the hollow profile is closed seamlessly in the direction of the front end of the vehicle, water can enter into the hollow profile through the rearwardly pointing opening. However, further penetration through the body shell and penetration into the interior of the vehicle is not possible, and so the only route for the water to leave is the inlet opening. This considerably reduces the outlay on sealing, which is now focused entirely on the inlet opening. The technique of forming by internal high pressure means that the hollow profile can be matched exactly to the desired space-dependent shape and cross section in a relatively simple manner in terms of the process.
Expedient refinements of the invention can be gathered from the subclaims; otherwise, the invention is explained in greater detail below with reference to an exemplary embodiment which is illustrated in the drawings.